Bioavailability of a bilberry anthocyanin extract and its impact on plasma antioxidant capacity in rats

Anthocyanins are secondary metabolites from the flavonoid family, frequently found in fruits and vegetables. They have been shown to possess beneficial health effects and various in vitro assays have highlighted their powerful antioxidant capacity. However, little is known about their metabolism after digestion and their antioxidant potency in vivo. The aim of this work was to evaluate anthocyanin bioavailability and to determine the impact of an anthocyanin‐rich diet on plasma antioxidant status in rats. Animals were fed for 8 days with a vitamin E‐deficient diet supplemented with a bilberry (Vaccinium myrtillus L.) anthocyanin extract providing daily 1.43 mmol anthocyanins kg^?1 body weight. An anthocyanin‐enriched diet significantly enhanced the plasma antioxidant capacity compared with a control diet (P < 0.0001). Moreover, anthocyanins were recovered in urine in the intact glycosidic forms in addition to unknown metabolites. Urinary excretion of bilberry anthocyanins and their metabolites was 0.71 ± 0.08 µmol per 24 h (ie 0.22% of the ingested dose). Anthocyanins and their corresponding aglycones were detected in caecal contents. After a single oral administration of the bilberry extract, native anthocyanins quickly (30 min) appeared in plasma. Hence, in spite of a low bioavailability, bilberry anthocyanin extract consumption has a positive effect on plasma antioxidant capacity. Copyright © 2005 Society of Chemical Industry     

Changes of Anthocyanins, Anthocyanidins, and Antioxidant Activity in Bilberry Extract during Dry Heating

ABSTRACT:  Thermal stability of 10 anthocyanins found in a bilberry extract was studied at different heating temperatures and times. Degradation of the 10 anthocyanins, delphinidin, cyanidin, petunidin, peonidin, and malvidin derivatives with different conjugated sugars, followed 1st-order reaction kinetics at heating temperatures 80, 100, and 125 °C. Though the degradation rate constants of anthocyanins were not significantly different from each other at the same heating temperature, they increased drastically when heating temperature was increased to 125 °C. At that temperature, the half-lives for all anthocyanins were less than 8 min. The degradation rate constants followed the Arrhenius equation. The trend of lower activation energy of the anthocyanins with arabinoside than with galactoside or glucoside was observed. These conjugated sugars were cleaved from the anthocyanins to produce their corresponding anthocyanidins or aglycones during heating. The production of anthocyanidins increased constantly and was converted from approximately 30% of the degraded anthocyanins when heated at 100 °C for up to 30 min. At 125 °C, the increase of anthocyanidins lasted for 10 min, after which the degradation rate of anthocyanidins exceeded the production rate. Antioxidant activities of the heated extracts were estimated by measuring DPPH (2, 2'-diphenyl-1-picrylhydrazyl) free radical scavenging activity. The extracts heated at 80 °C for 30 min, 100 °C for 10 and 20 min, and 125 °C for 10 min had higher free radical scavenging capability than unheated extract.     

Effect of enzyme‐aided pressing on anthocyanin yield and profiles in bilberry and blackcurrant juices

Bilberries (Vaccinium myrtillus) and blackcurrants (Ribes nigrum) were treated with extensive dosages of commercial cell wall degrading enzyme preparations, i.e. Econase CE, Pectinex Ultra SP‐L, Pectinex Smash, Pectinex BE 3‐L and Biopectinase CCM. The enzymes were dosed based on the polygalacturonase activity. The juice yield was improved in both berries as a result of the enzymatic treatment. The improvement was more pronounced with blackcurrants owing to their thicker cell walls. The impact of the enzymatic treatment on anthocyanins present in the juices was investigated using HPLC‐DAD. The enzyme preparations affected the contents and composition of anthocyanins in the juices. Pectinex Ultra SP‐L, Pectinex Smash, Pectinex BE 3‐L and Biopectinase CCM increased the total content of anthocyanins by 13–41% in the bilberry juices and by 18–29% in the blackcurrant juices. Econase CE, however, produced a dramatic decrease in the total anthocyanin content in the bilberry juice due to its enzyme profile, whereas no such effect was observed with the blackcurrant juice. All the enzyme mixtures tested produced a total or extensive loss of anthocyanidin galactosides in bilberry juice. Commercial enzyme preparations used in the production of berry juices can improve extraction of anthocyanins into the juice. However, they may effectively hydrolyse certain glycosides and thus affect the profile of extracted anthocyanins. Copyright © 2005 Society of Chemical Industry     

Effect of pectinolytic juice production on the extractability and fate of bilberry and black currant anthocyanins

Bilberries (Vaccinium myrtillus L.) and black currants (Ribes nigrum L.), dark blue berries rich in anthocyanins, were processed with an aid of commercial pectinolytic enzyme preparations, and the effect of processing on berry anthocyanins was investigated. The enzyme preparations were dosed based on their polygalacturonase activity from 1 to 100 nkat/g of berry mash. The juice yields were determined by weighing, and anthocyanin analyses were performed with HPLC. The bilberry and black currant juice yields increased significantly in enzyme-aided treatments with comparison to control, even with the lowest (1 nkat/g) polygalacturonase dosage. The anthocyanin yield increased by up to 83% for bilberries and up to 58% for black currants in enzyme-aided treatments as compared to control. The results showed that higher polygalacturonase dosage was needed for black currant to achieve the maximal juice and anthocyanin yields than for bilberries. The stability and the profile of extracted anthocyanins were greatly affected by the glycosidase side activities present in the enzyme preparations, which were able to hydrolyze certain anthocyanins to the corresponding aglycones. In addition, the data indicate that anthocyanidin rutinosides were more easily extracted than those of glucosides, which prevailed over the arabinosides and galactosides. Thus, prior to processing it is important to know the intact anthocyanin structures of the raw material, and the activity profile of the enzyme preparation to obtain optimal anthocyanin extractability and enzyme dosage.     

安庆地区5个高产蓝莓品种花青素稳定性研究

目的 考察安庆地区5个高产蓝莓品种（奥尼尔、灿烂、海岸、巴尔德温、密斯蒂）花青素加工稳定性。方法 以花青素保存率为评价指标,分别研究了环境因素（pH、光照、温度）和添加物（金属离子、氧化剂、还原剂、蔗糖、食盐、柠檬酸、山梨酸钾）对5个品种蓝莓花青素稳定性的影响。结果 5个品种蓝莓花青素对pH、光照和高温比较敏感;Zn2+、蔗糖、柠檬酸、山梨酸钾能增强花青素稳定性;花青素与Cu2+、Ca2+共存超过5天,降解速度加快;Fe3+、H2O2、Na?SO?和浓度高于5%的食盐能破坏花青素的稳定性。结论 奥尼尔蓝莓花青素稳定性最弱,巴尔德温中花青素稳定性最强。研究结果能为蓝莓及花青素产品生产提供参考。     

基于组合色谱技术的蓝莓果实中花色苷元制备

首先采用液液萃取及大孔树脂层析技术研究花色苷的制备方法,萃取剂为乙酸乙脂,大孔树脂为Amberlite XAD-7HP,在此基础上制得花色苷粗提液。花色苷经酸水解、浓缩后,采用固相萃取技术（C18小柱）对花色苷元进行除酸、除糖处理,制得了纯度为70.2%的花色苷元混合物。最后采用半制备型高效液相色谱技术实现4 种主要花色苷元单体的分离,分别为飞燕草素（纯度98.2%）、矢车菊素（纯度96.3%）、牵牛花素（纯度92.6%）、锦葵色素（纯度90.5%）。本研究可为花色苷元的规模化制备及后期功能活性研究提供技术参考和依据。     

LC‐MS identification of anthocyanins in boysenberry extract and anthocyanin metabolites in human urine following dosing

The anthocyanin composition of boysenberry (Rubusloganbaccus × baileyanus Britt) extract was determined by LC‐ESI‐MS. Four anthocyanins were identified, all comprising a cyanidin‐anthocyanidin‐type skeleton. The two major components were identified as the disaccharide cyanidin‐3‐O‐sophoroside and the monosaccharide cyanidin‐3‐O‐glucoside. The two less abundant components were identified as the rutinosides, cyanidin‐3‐O‐2^G‐glucosylrutinoside and cyanidin‐3‐O‐rutinoside, respectively. These same four anthocyanins were also detected in human urine following a dosing study with boysenberry extract indicating that glycosylated anthocyanins can be absorbed from the gut and excreted intact in the urine. Several anthocyanin metabolites were also detected in the urine and were identified by LC‐ESI‐MS as monoglucuronides of peonidin, cyanidin and pelargonidin. The results suggest that anthocyanins consumed as part of a diet are bioavailable and are present as intact or metabolized forms in the body. Copyright © 2004 Society of Chemical Industry     

Blackcurrant anthocyanins modulate CCL11 secretion and suppress allergic airway inflammation

CCL11, a chemokine, is linked to the early development of airways eosinophilia in allergic asthma. Therefore, CCL11 production is a target for abrogating eosinophilic‐driven airway inflammation. Blackcurrants are high in compounds that regulate inflammation, particularly anthocyanins. In this study, we investigated the effect of oral blackcurrant supplementation on allergen‐induced eosinophilia and CCL11 production; we also profiled key compounds in blackcurrants that were linked to this effect. Ten milligram per kilogram (total anthocyanins) of a commercially available, anthocyanin‐rich New Zealand “Ben Ard” blackcurrant extract (“Currantex 30”) attenuated ovalbumin‐induced inflammation, eosinophilia (by 52.45 ± 38.50%), and CCL11 production (by 48.55 ± 28.56%) in a mouse model of acute allergic lung inflammation. Ten blackcurrant polyphenolic extracts were also found to suppress CCL11 secretion by stimulated human lung epithelial cells in vitro. Correlation analysis identified potential blackcurrant polyphenolic anthocyanin constituents specifically delphinidins and cyanidins, involved in CCL11 suppression. Our findings show oral supplementation with New Zealand blackcurrant is effective in reducing lung inflammation, and highlight the potential benefit of developing cultivars with specific polyphenolic profiles for the creation of functional foods with desirable biological activity.     

Effects of casein- and whey protein–dextran conjugates on the stability of bog bilberry anthocyanin extract

Bog bilberry ( Vaccinium uliginosum ) contains a high concentration of anthocyanins. Anthocyanin stability depends on many factors, including pH, temperature and composition of food matrices in a product, such as protein and polysaccharide. The effect of casein–dextran and whey protein–dextran conjugates on the stability of bog bilberry anthocyanin extract (BBAE) was investigated in an accelerated model system. Cyanidin-3-glucoside was the main anthocyanin (79%) found in BBAE. The cyanidin-3-glucoside content, absorbance and ABTS [2, 2-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity of BBAE significantly ( P  < 0.05) decreased after heating at pH 8.0 and 80 °C for 60 min. The addition of casein–dextran and whey protein–dextran conjugates significantly ( P  < 0.05) prevented cyanidin-3-glucoside from degradation, and increased the absorbance and ABTS radical scavenging activity of heated BBAE. The protection of casein–dextran conjugate on BBAE was significantly higher ( P  < 0.05) than that of whey protein–dextran conjugate. The results suggest that protein–dextran conjugates have the ability to stabilise BBAE.     

Berry anthocyanins: isolation,identification and antioxidant activities

Anthocyanins from bilberry, blackcurrant and cowberry were isolated for antioxidant evaluation. Individual compounds were identified and quantified using HPLC and HPLC/ESI–MS techniques. Antioxidant and radical‐scavenging capacities of the isolates were studied in emulsified methyl linoleate and human low‐density lipoprotein (LDL) in vitro and in the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) test. The total anthocyanin contents in the phenolic extracts of bilberry, blackcurrant and cowberry were 6000, 2360 and 680 mg kg^?1 fresh weight respectively. There were four dominant compounds in blackcurrant (glucosides and rutinosides of cyanidin and delphinidin), three in cowberry (monoglycosides of cyanidin) and 15 in bilberry (monoglycosides of cyanidin, delphinidin, malvidin, peonidin and petunidin). Quantification as cyanidin‐3‐glucoside equivalents gave markedly lower results regarding the total anthocyanin concentration and the content of individual delphinidin and malvidin compounds compared with quantification based on corresponding standard compounds. Berry anthocyanins were highly active radical scavengers in the DPPH test and effective antioxidants in emulsion and human LDL. Copyright © 2003 Society of Chemical Industry     

Qualitative und Quantitative Analyse der Anthocyane in Schwarzen Apfelbeeren (Aronia melanocarpa Michx. Ell.) mittels TLC, HPLC und UV/VIS-Spektrometrie

Total anthocyanin content and qualitative and quantitative anthocyanin composition in black chokeberries [Aronia melanocarpa (Michx.) Elliott] were determined by TLC, HPLC and UV/VIS methods. After ethanol extraction and cleaning operations we found, in different varieties of black chokeberries (Nero, Rubina and Viking), between 650 mg and 850 mg total anthocyanins per 100 g dry weight. The anthocyanin composition was analysed; (cyanidin was the only aglycon (anthocyanidin) found and the monosaccharides galactose (68.9%), arabinose (27.5%), xylose (2.3%) and glucose (1.3%) were identified. The quantitative distribution is given in parentheses. In comparison with other berries and fruits, which are rich in anthocyanins, black chokeberries have a simple anthocyanin spectrum, but a many times higher anthocyanin content. For that reason chokeberries are of special interest as a source for a natural colourant.     

Qualitative und Quantitative Analyse der Anthocyane in Schwarzen Apfelbeeren (Aronia melanocarpa Michx. Ell.) mittels TLC,HPLC und UV/VIS-Spektrometrie

Total anthocyanin content and qualitative and quantitative anthocyanin composition in black chokeberries [Aronia melanocarpa (Michx.) Elliott] were determined by TLC, HPLC and UV/VIS methods. After ethanol extraction and cleaning operations we found, in different varieties of black chokeberries (Nero, Rubina and Viking), between 650 mg and 850 mg total anthocyanins per 100 g dry weight. The anthocyanin composition was analysed; (cyanidin was the only aglycon (anthocyanidin) found and the monosaccharides galactose (68.9%), arabinose (27.5%), xylose (2.3%) and glucose (1.3%) were identified. The quantitative distribution is given in parentheses. In comparison with other berries and fruits, which are rich in anthocyanins, black chokeberries have a simple anthocyanin spectrum, but a many times higher anthocyanin content. For that reason chokeberries are of special interest as a source for a natural colourant.     

Degradation kinetics of pigment,colour and stability of the antioxidant capacity in juice model systems from six anthocyanin sources

Coloured model juices with extracts from several species of commonly consumed vegetables rich in anthocyanins (eggplant peel, strawberry, grape, bilberry, red raspberry and plum peel) were studied in detail. The model juices prepared at pH 4.5 were stored in darkness for 17 weeks at 20 °C. The kinetics of anthocyanin degradation, colour and stability of the antioxidant capacity were measured during storage. The anthocyanins were determined identifying delphinidins, cyanidins, petunidins, pelargonidins, peonidins and malvidins. The extraction yields ranged from 2.3% to 13.3%. The level of anthocyanins in the model juices prepared with the extracts ranged between 4 and 158 mg L^–1. The results showed a good correlation between the anthocyanin concentration and the time of storage, with determination coefficients varying from R² = 0.9470 to R² = 0.9855. The eggplant peel, grape and plum peel anthocyanins showed the highest half‐life and D values that were higher than those of 12 and 17 weeks, respectively. The antioxidant capacity showed a high stability during the time of storage for all the model juices, showing the eggplant peel model juice the highest values.     

Flavylium salts, anthocyanidins and anthocyanins. I. Structural transformations in acid solutions

Structural transformations in acid solutions of some flavylium salts, anthocyanidins and anthocyanins have been studied by spectrum and pH measurements. The stabilities of the coloured cationic forms were increased by substitution of hydroxyl groups in positions 7 and 5 of the A ring, but decreased by hydroxylation in the 3-position (anthocyanidins). The anthocyanin 3,5-diglycosides were stronger acids than the 3-glycosides. The effect of substituents on anhydro-base formation is also described. The results are discussed in relation to the possible use of flavylium salts as food additives.     

Phenolics of Vaccinium berries and other fruit crops

The concentrations and profiles of phenolics of selected fruit crops common in the Western diet, including several Vaccinium species, were examined to better understand how these crops may be useful sources of phenolic phytochemicals. Vaccinium fruit had a high phenolic concentration compared to non‐Vaccinium fruit. Some Vaccinium fruit were particularly rich in certain phenolic subgroups, especially anthocyanins and pro‐anthocyanidins. Among the pro‐anthocyanidin oligomers measured using fluorometric and mass spectroscopic detection, the trimers and tetramers were most abundant, while pro‐anthocyanidins with a degree of polymerization greater than 8 were least abundant. As biomedical studies determine which phenolic structures are associated with particular bioactivities, information on the phenolic concentration and profile of selected species will be useful in developing specific uses for fruit crops in human health. Methods were compared to assess the usefulness of simpler versus more sophisticated means of phenolic analysis. The phenolic components of fruit extracts were purified approximately 20‐fold, and not qualitatively altered, by C18 solid‐phase extraction. However, fruit extracts obtained from C18 solid‐phase extraction differed in their relative abundance of phenolic components. Colorimetric and HPLC‐DAD measures of phenolic concentration were correlated (R² = 0.79), as was pro‐anthocyanidin concentration detected fluorometrically and by mass spectrometry (R² = 0.44). Copyright © 2007 Crown in the right of Canada and Society of Chemical Industry     

Anthocyanin Degradation of Blueberry–Aronia Nectar in Glass Compared with Carton during Storage

ABSTRACT: Blueberry–aronia nectar is known as a rich source of anthocyanins, which are mostly destroyed during commercial storage of the product. The factors influencing the rate of degradation are connected to the oxygen protection offered by the packaging, as well as the type of anthocyanidin and the amount of glycosylated sugar. The current study was aimed to compare the stability of total anthocyanin between glass and carton packaging as well as to determine the stability of individual anthocyanin with respect to aglycone and glycosylated sugar. The degradation rate of total anthocyanin degradation rate was 22% higher in carton packaging than glass bottle. The ranking order of the stability of individual anthocyanin with respect to aglycone was as follows (from the most to least stable): cyanindin > peonidin > petunidin > malvidin = delphinidin. The ranking order of the stability of anthocyanins with respect to glycosylated sugars was as follows (from the most to least stable): glucose > galactose > arabinose. As individual anthocyanins have different degradation rates this study can be used to determine the most stable natural colorant and the most sensitive antioxidant among the anthocyanins tested.     

Pressing Effects on Yield, Quality, and Nutraceutical Content of Juice, Seeds, and Skins from Black Beauty and Sunbelt Grapes

ABSTRACT: The effects of hot and cold (nonheated) pressing on yield, quality components, and nutraceutical content of juice, grapes, and press fractions (seeds and skins) from Black Beauty ( Vitis rotundifolia ) and Sunbelt ( Vitis labruscana L.) grape cultivars were evaluated. Heating the must before pressing increased juice yield, titratable acidity, red color, brown/yellow pigments, and darkness and decreased the press fraction yield and juice pH in both cultivars. Sunbelt juice from the heated must had the highest yield (786 L/metric ton), red color, brown/yellow pigments, and darkness. Black Beauty nonheated must had the largest press fraction (43%) but the lowest red color, brown/yellow pigments, and darkness in the juice. The juice generally had less total phenolics, total anthocyanins, and oxygen radical absorbance capacity (ORAC) than the whole grapes. The juice from heated Black Beauty and Sunbelt musts had the highest total phenolics (1354 and 1937 mg/L, respectively) and anthocyanins (414 and 513 mg/L, respectively). Although the data for seeds and skins are on a dry basis, the press fractions had higher levels of phenolics and ORAC than the whole grapes and juice. The dried seeds had more phenolics and less anthocyanins than the skins. The highest total phenolic level (95338 mg/kg) equivalents and ORAC level (1100 μmol trolox/g) was in Black Beauty seeds from nonheated must. The skins of nonheated Sunbelt had the highest anthocyanins (11889 mg/kg). Because the press fractions of both cultivars had high ORAC values and total phenolic levels, products with nutraceutical benefits could be developed.     

Degradation Index for Quality Evaluation of Commercial Dietary Supplements of Bilberry Extract

In recent years, many anthocyanin‐containing dietary supplements of various dosages and formulations have been sold through advertising their large number of beneficial effects. On the other hand, there is an increased risk of distributing deteriorated supplements to consumers due to lax regulations, because in Japan these supplements are classified as food. Spectrophotometric methods are commonly used to control the quality of supplements. However, these methods have limitations with regard to assessing deterioration. In this study, we evaluated a new index for detection of deteriorated products. The stability of 3 formulations and the quality of 20 supplements were investigated by ultra‐high performance liquid chromatography, which is superior to spectrophotometry for identifying and quantifying individual anthocyanins. The stability was not only affected by storage temperature but also by formulation. We defined “Degradation Index” (DI) as an indicator of the deterioration of supplements. Of 20 supplements investigated, the DI of 5 supplements was more than 3‐fold the value of Bilberon‐25, and the worst one was 12.7‐fold. These results suggest that DI could be a useful quality control index for detecting deteriorated supplements.     

Dietary intake of anthocyanins and risk of cardiovascular disease: A systematic review and meta-analysis of prospective cohort studies

Abstract

Accumulating evidence suggests flavonoid intake is associated with reduced risk of non-communicable diseases. We aimed to systematically determine and quantify the potential association between dietary anthocyanin intake and risk of cardiovascular diseases (CVD). A systematic literature search of studies reporting anthocyanin intake and risk of fatal or nonfatal CVD was performed using SCOPUS, MEDLINE, CINAHL and Cochrane Library. The relative risk (RR) or hazard ratio (HR) of highest category of anthocyanin foods were pooled in a random-effects meta-analysis. Subgroup analysis were conducted to determine possible sources of heterogeneity. The meta-analysis suggested intake of dietary anthocyanins and reduced risk of CHD (RR?=?0.91, 95% CI: 0.83, 0.99; I²?=?12.0, P_h?=?0.337) and CVD mortality (RR?=?0.92, 95% CI: 0.87, 0.97; I²?=?0.0, P_h?=?0.584). However, there was no relationship between the intake of these compounds and reduced risk of MI, stroke or total CVD. Subgroup analysis determined reduced risk of CHD and CVD mortality was more prominent for anthocyanidin intake, as opposed to anthocyanin or berries. Our systematic review and meta-analysis provides evidence that anthocyanins, specifically anthocyanidins, reduce the risk of CHD and CVD mortality. Further randomized controlled trials on anthocyanin intake and CVD risk factors are needed to support these findings.